STMicroelectronics STM32L151R6T6

Overview

STM32L151R6T6 from STMicroelectronics is an ultra-low-power 32-bit ARM® Cortex®-M3 microcontroller featuring 128 KB Flash, 32 KB SRAM, 4 KB EEPROM with ECC, 12-bit ADC (1 Msps, up to 24 channels), and dual 12-bit DACs - deployed in battery-powered IoT sensor nodes requiring sub-µA standby current and integrated analog signal conditioning.

For engineers reviewing the STM32L151R6T6 datasheet, STM32L151R6T6 pinout, STM32L151R6T6 application, or STM32L151R6T6 equivalent, key selection criteria include ultra-low-power mode timing (0.28 µA Standby), USB 2.0 full-speed interface with internal 48 MHz PLL, and capacitive touch sensing support for human-interface devices.

Technical Context

The STM32L151R6T6 integrates a Cortex-M3 core operating at up to 32 MHz with dynamic voltage scaling, memory protection unit (MPU), and multiple clock sources including HSE (1–24 MHz), LSE (32.768 kHz RTC), and factory-trimmed 16 MHz HSI (±1%). Its power architecture supports five low-power modes - Standby (0.28 µA), Stop + RTC (1.38 µA), and Low-power Run (10.9 µA) - enabling multi-year operation on coin-cell batteries.

Analog subsystem includes two ultra-low-power comparators with window mode and wake-up capability, temperature sensor, VREFINT reference, and dedicated ADC/DAC peripherals operating down to 1.8 V supply. Communication interfaces comprise 3x USART (with IrDA/ISO 7816), 2x SPI (16 Mbit/s), 2x I²C (SMBus/PMBus), and USB 2.0 full-speed with internal transceiver and PLL.

Key Specifications

Pinout & Package

LQFP64 (10 × 10 mm, 0.5 mm pitch) package with 51 user I/O pins, including 42 5V-tolerant GPIOs, 3 dedicated USB DP/DM pins, and 3 independent power domains (VDD, VDDA, VSSA).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-power microcontroller applications.

Compared with STM32L151R6T6, the STM32L071RBT6 sacrifices EEPROM, DACs, and USB for lower cost and smaller die size, while the EFM32PG12B500F1024GL125 trades integrated USB and ultra-low standby for higher compute throughput and memory - making STM32L151R6T6 optimal for balanced analog+USB+low-power embedded systems.

Availability

STM32L151R6T6 is available at Aetrix Electronics and suitable for smart utility meters, wearable health monitors, industrial wireless sensor nodes, and medical point-of-care devices requiring stable component supply across multi-year production cycles.

Supply support for STM32L151R6T6 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power management ICs, MEMS, and automotive semiconductors since 1987.

The STM32L1 series targets ultra-low-power embedded applications - optimized for battery-operated devices demanding sub-µA sleep, integrated analog, and secure firmware execution in constrained environments.

FAQ

What is the maximum operating frequency and core type of the STM32L151R6T6?

The STM32L151R6T6 features an ARM Cortex-M3 32-bit core rated for up to 32 MHz operation. It achieves 1.25 DMIPS/MHz (Dhrystone 2.1) and includes a Memory Protection Unit (MPU) for secure task isolation. The core supports Thumb-2 instruction set and operates across the full 1.65–3.6 V supply range with dynamic voltage scaling to optimize performance versus power.

Does the STM32L151R6T6 support USB functionality without external components?

Yes - the STM32L151R6T6 integrates a full-speed USB 2.0 transceiver with an internal 48 MHz PLL, eliminating the need for an external crystal or PHY IC. PA11 (DP) and PA12 (DM) are dedicated USB pins with built-in ESD protection and slew-rate control. The device supports USB device mode only and requires no external passive components for basic enumeration and data transfer.

How many analog-to-digital converter (ADC) channels does the STM32L151R6T6 support, and what is its resolution?

The STM32L151R6T6 integrates a single 12-bit ADC with up to 24 external input channels and 1 Msps sampling rate. It supports hardware oversampling, injected/conversion sequences, and operates down to 1.8 V supply. Additional analog resources include two 12-bit DACs with output buffers, two ultra-low-power comparators, temperature sensor, and internal voltage reference (VREFINT).

What low-power modes are available, and what is the lowest achievable current draw?

The STM32L151R6T6 offers five low-power modes: Sleep, Low-power Run, Low-power Sleep, Stop, and Standby. The lowest current is 0.28 µA in Standby mode with three wakeup pins enabled. With RTC active, Standby draws 1.11 µA; Stop mode consumes 0.44 µA (16 wakeup lines) or 1.38 µA with RTC. Wake-up time from Stop is under 8 µs - critical for responsive event-driven systems.